XXIX. ] RIGA FIR, 247 
There are, besides the hand-masts, many straight 
and fair-grown trees that measure less than 24 inches in 
circumference at the base, which are simply termed 
spars, or poles. There are also a few pieces occasionally 
met with that exceed the maximum size of the hand- 
mast, which are generally dressed approximately to an 
octagonal form, and then, as at Dantzic and elsewhere, 
they are called inch masts. 
In ordinary specifications for building, it is stipulated 
the Fir is to be from Dantzic or Riga, as if they were 
equal in quality;- but my experiments on Riga Fir, 
though not nearly so numerous as those on Dantzic, 
prove the former to be slightly inferior to the latter. 
Tables CXXII. to CXXVIII. and CXXIX. to CKXXII. 
show that the strength of the Riga is to that of Dantzic 
Fir as follows, viz. :— 
Transversely as 150 : 219 or, it is weaker by about 31 per cent. 
Tensilely »» 4051 : 3231,, 5, stronger ,, 20 sy 
Vertically ,, 5247 : 6948,, ,, weaker ” 24 ” 
TABLE CXXIX.—Fir (RIGA). 
Transverse Experiments. 
Deflections. 3 
. oar Ou Weight Weight 
Number | with the | Afterthe| At required | ‘6.2 required 
of the | apparatus| weight | thecrisis | to break @& | specific] '° Fe! 
Woo 
specimen, 
weighing was oO each gravity} 7 Square 
390 lbs. | removed. | breaking. | piece. 600, inch. 
Inches. Inch. Inches. Ibs. Ibs. 
I 1°25 ‘10 3°00 580 524 | 664 | 145’00 
2 1°00 “10 3°75 797 584 | 726) 176°75 
3 1°50 “10 3°30 498 518 | 577 | 124°50 
4 1°50 05 4°50 615 | 534] 691 | 153°75 
5 1°35 “10 3°85 677 579 | 712 | 169°25 
6 1°15 ‘10 3°35 523 516 | 608} 130°75 
Total .| 7°75 55 21°75 | 3,600 | 3246 | 3978 | 900°00 
Average} 1°292 092 37625 | 600 541 | 663] 150°00 
Remarks.—No. 1 broke a little short ; 2 and 3 with fractures 9 inches in length; in 
4 5, and 6, the fractures were longer and splintery. 
